London Underground is ready to launch a system which allows people to pay for train journeys using their mobile phones.

Officials from Transport for London, mobile maker Nokia and phone network O2 are understood to be preparing final details of a handset with a built-in Oyster card.

It is believed that the scheme will allow tube travellers to pay for their journeys simply by swiping a compatible mobile phone across the ticket-reading machine. The system could also be used for bus journeys, trams and some overland train journeys around the capital.